A wide variety of medical conditions and disorders have been successfully treated using an implantable stimulator. Implantable stimulators typically stimulate internal tissue, such as a nerve, by emitting an electrical stimulation current according to programmed stimulation parameters.
One type of implantable stimulator is known as a microstimulator. Microstimulators are typically characterized by a small, cylindrical housing containing electronic circuitry that produces the desired electric stimulation current between spaced electrodes. These stimulators are implanted proximate to the target tissue so that the stimulation current produced by the electrodes stimulates the target tissue to reduce symptoms or otherwise provide therapy for a wide variety of conditions and disorders. Exemplary microstimulators are described in U.S. Pat. Nos. 5,312,439; 5,193,539; 5,193,540; and 5,405,367; 6,185,452; and 6,214,032. All of these listed patents are incorporated by reference in their respective entireties.
Another type of implantable stimulator is known as an implantable pulse generator (IPG). A typical IPG includes a multi-channel pulse generator housed in a rounded titanium case. The IPG is generally coupled to a lead with a number of electrodes disposed thereon. Stimulation current is generated by the IPG and delivered to target tissue via the electrodes on the lead. Exemplary IPGs are described in U.S. Pat. Nos. 6,381,496; 6,553,263; and 6,760,626. All of these listed patents are incorporated by reference in their respective entireties.
As will be readily appreciated, a key part of patient treatment using an implanted stimulator is the proper placement of the stimulator such that the stimulation electrodes are proximate to the stimulation site to be stimulated. If the stimulation electrodes are optimally placed near the stimulation site, stimulation can be affected over a wide range of parameters and power consumption can be minimized. However, optimal placement of a stimulator within a patient is often difficult to accomplish.